Drive unit of a vehicle able to be driven by muscle power and / or motor power

Abstract

The invention relates to a drive unit (1) of a vehicle (100) able to be driven by muscle force and / or motor force, comprising a motor (2) with an output shaft (22), a crank shaft (3) and a transmission (4), wherein the transmission (4) is configured for torque transmission between the output shaft (22) and the crank shaft (3), wherein the output shaft (22) is arranged coaxially to the crank shaft (3), and wherein the transmission (4) is designed as a spur gear transmission.

Description

[0001] Description

[0002] title

[0003] Drive unit of a vehicle that can be operated with muscle power and / or motor power

[0004] State of the art

[0005] The present invention relates to a drive unit of a vehicle operable with muscle power and / or motor power, and to a vehicle operable with muscle power and / or motor power.

[0006] Drive units for vehicles powered by human and / or motor power, such as electric bicycles, are known, which comprise gears between a motor and a crankshaft. A spur gear arrangement is often used, with a motor whose output shaft is arranged parallel to the crankshaft and spaced from it. Drive units with a motor arranged coaxially to the crankshaft, with a planetary gear for torque transmission, are also known.

[0007] Disclosure of the invention

[0008] The drive unit according to the invention with the features of claim 1 is distinguished by a particularly advantageous design and high efficiency. In particular, a particularly compact overall design of the drive unit can be enabled, while at the same time a high degree of power transmission efficiency can be enabled. This is achieved according to the invention by a drive unit of a vehicle operable with muscle power and / or motor power, preferably an electric bicycle, comprising a motor with an output shaft, a crankshaft, and a transmission. The transmission is designed and arranged to transmit torque between the output shaft of the motor and the crankshaft. The output shaft, and preferably the motor, is arranged coaxially to the crankshaft. Furthermore, the transmission is designed as a spur gear transmission.

[0009] In other words, a coaxial arrangement of the engine output shaft and the crankshaft is provided, whereby torque transmission between the output shaft and the crankshaft is enabled via the transmission designed as a spur gear.

[0010] In particular, a spur gear is considered to be a gear with multiple gears, wherein the toothing of all gears is formed, in particular exclusively, on an outer circumference of the corresponding gear. In particular, the respective gears that mesh with each other are arranged rotatably about separate axes.

[0011] The drive unit thus offers the advantage that the coaxial arrangement of the output shaft and crankshaft, and thus preferably also of the motor and crankshaft, enables a particularly compact design of the drive unit. This allows the motor, which often takes up a significant portion of the overall installation space of the drive unit, to be optimally positioned coaxially with the crankshaft. This arrangement has a particularly advantageous effect on the compact overall design of the drive unit when the largest gear of the transmission is located on the crankshaft.This allows the remaining transmission volume, for example, to extend only slightly beyond the axial projection surface of the motor, allowing this volume to be comparatively narrow and, in particular, positioned relatively centrally in the axial direction, which has a further advantageous effect on the design of the drive unit. Furthermore, the drive unit is characterized by low costs due to fewer and relatively simple components. This also enables a low weight of the drive unit.

[0012] The subclaims contain preferred developments of the invention. The transmission preferably has an intermediate shaft which is arranged parallel to the crankshaft. This means that in particular an intermediate shaft axis of the intermediate shaft is arranged parallel to a crankshaft axis of the crankshaft. The transmission is designed to transmit torque between the output shaft and the crankshaft via the intermediate shaft. This means that the torque is transmitted from the output shaft of the engine via the intermediate shaft to the crankshaft. This allows the transmission to be provided with a predetermined gear ratio between the output shaft and crankshaft in a particularly simple manner and with few components. In addition, a gear ratio can be easily adjusted, for example, by scaling the intermediate shaft, in particular with corresponding gears.

[0013] Particularly preferably, the transmission comprises a first gear and a second gear. The first gear and the second gear are each connected to the intermediate shaft in a rotationally fixed manner. For example, the first gear, the second gear, and the intermediate shaft can be formed together as a single, integral component. This allows for a simple, cost-effective, and robust design.

[0014] Alternatively, the transmission preferably has a first gear and a second gear and a freewheel. One of the two gears, i.e. the first gear or the second gear, is connected to the intermediate shaft in a rotationally fixed manner. The freewheel is arranged between the other gear and the intermediate shaft. In particular, the freewheel is designed to be able to switch between a rotationally fixed connection and a relatively freely rotatable connection between the corresponding gear and the intermediate shaft. The freewheel preferably locks in the drive direction of the motor and opens when the motor is at a standstill or during actuation of the cranks. Alternatively or additionally, the freewheel can be designed to be controllably actuated, for example by means of a control unit.In particular, the freewheel allows the engine to be decoupled from the crankshaft, for example, to deactivate the engine support, especially when a predetermined vehicle speed is exceeded. The transmission preferably has a motor gearing formed on the output shaft. In particular, a portion of the output shaft is thus designed as a gear with the motor gearing. The first gear is in mesh with the motor gearing. This further advantageously facilitates a compact, simple, and cost-effective design.

[0015] The transmission further preferably has a third gear that can be connected to the crankshaft in a rotationally fixed manner. In particular, the third gear can additionally be arranged to rotate relative to the crankshaft in a freewheel mode. The third gear meshes with the second gear of the intermediate shaft. In particular, the torque can thus be transmitted from the intermediate shaft to the crankshaft via the third gear.

[0016] Particularly preferably, the drive unit further comprises a freewheel between the third gear and the crankshaft. In particular, the freewheel is designed to be able to switch between a rotationally fixed connection and a relatively freely rotatable connection between the third gear and the crankshaft. Preferably, the freewheel locks in the drive direction of the engine and opens when the engine is stationary and during actuation of the cranks. Alternatively or additionally, the freewheel can be designed to be controllably actuated, for example by means of a control unit. In particular, the freewheel can thus be decoupled from the crankshaft, for example to switch off the engine assistance, in particular when a predetermined vehicle speed is exceeded.

[0017] For example, in a preferred alternative embodiment, the third gear can be formed in a rotationally fixed manner with a hollow shaft on which the output interface is arranged. In this case, the freewheel between the third gear and the crankshaft can act as a driver's freewheel, i.e., to enable a rotationally fixed or relatively freely rotatable connection between the output interface and the crankshaft.

[0018] Preferably, the transmission is designed as a two-stage spur gear. This means that two spur gear stages are provided to provide a predetermined gear ratio between the output shaft and the crankshaft. This allows for optimal torque transmission of the drive unit for use in an electric bicycle, while maintaining a compact design and simple construction.

[0019] Particularly preferably, the motor has a rotor that is non-rotatably connected to the output shaft. In particular, the rotor is designed coaxially with the output shaft. For example, the rotor and output shaft can be formed as a single, integral component. This allows for a simple and robust design with few components, thus also being cost-effective and lightweight.

[0020] The output shaft is preferably designed as a hollow shaft. The crankshaft is rotatably mounted within the output shaft. Preferably, at least one bearing is provided between the crankshaft and the drive shaft for rotatable support. For example, the bearing can be designed as a needle bearing for a particularly compact design in the radial direction. By designing the output shaft as a hollow shaft and the crankshaft passing through it, a particularly compact geometry of the drive unit can be provided. Furthermore, flexible relative positioning of the drive unit components along the axial direction of the crankshaft can be enabled.

[0021] More preferably, the drive unit further comprises two bottom brackets. The crankshaft is rotatably mounted in a housing of the drive unit by means of the two bottom brackets. The bearings can be designed, for example, as ball bearings, such as deep groove ball bearings, or the like.

[0022] The drive unit preferably further comprises a detection device configured to detect a bearing force at the output-side bottom bracket. The output-side bottom bracket is considered to be, in particular, the one of the two bottom brackets that is arranged closer to an output interface of the crankshaft, to which an output element can be fastened. The output element is preferably designed as a chainring. Alternatively, another output element can preferably be provided that is configured to be connected to a transmission element in order to enable torque transmission from the crankshaft to a drive wheel of the vehicle. Based on the determined bearing force, a pedaling force and / or a pedaling torque applied by the rider can preferably be determined.Based on this, a driver request can preferably be determined, on the basis of which the controlled generation of the motor-assisting engine torque of the drive unit takes place.

[0023] Particularly preferably, the detection device comprises two force sensors. Each force sensor is configured to detect a force along a predetermined direction, in particular wherein the two directions of the force sensors are different. The detection device is configured to determine a bearing force direction and a bearing force magnitude of the bearing force at the output-side bottom bracket based on the forces detected by the two force sensors. Preferably, the two force sensors are arranged at different circumferential positions around the circumference of the bottom bracket. This makes it easy to determine, for example, the direction and magnitude of a current bearing force at the output-side bearing. This determination of the direction and magnitude of the bearing force is preferably based on a previously known relative installation position of the two force sensors to one another.A variety of force sensors can be used, suitable for detecting mechanical forces acting in a predetermined direction. For example, the force sensors can be designed to detect tensile forces and / or compressive forces. Particularly preferably, each of the two force sensors has a strain gauge and / or a piezo element. This allows, for example, a force in the tangential direction relative to the crankshaft to be detected. Furthermore, the bearing force can thus be detected in a particularly simple, cost-effective, and space-saving manner.

[0024] The crankshaft preferably has an output interface which is designed for connection to an output element. A chainring can preferably be provided as the output element. Alternatively, another output element can preferably be provided which is designed for connection to a transmission element, such as a chain, in order to enable torque to be transmitted from the crankshaft to a drive wheel of the vehicle. For example, the output interface can thus be a receiving element for an output element, such as in particular a chainring. The motor is arranged on a side of the transmission facing the output interface. This means that the motor is arranged closer to the output element than the transmission in the axial direction of the crankshaft. Alternatively, the motor is preferably arranged on a side of the transmission facing away from the output interface.This means that in this case, the transmission is arranged closer to the output interface than the engine. In other words, the engine can be arranged on the right or left with respect to the direction of travel of a vehicle on which the drive unit can be arranged. Preferably, if the engine is arranged on the left, and if the output interface is designed, for example, as a hollow shaft, a freewheel, in particular in the form of a driver's freewheel, can be provided between the crankshaft and the output interface in an alternative embodiment.

[0025] More preferably, the drive unit further comprises a printed circuit board, which is preferably part of a control unit of the drive unit, or comprises a control unit. The printed circuit board is arranged in the axial direction of the crankshaft between the motor and the transmission. In particular, in this case, all elements of the transmission, i.e., gears, and the motor are arranged on opposite sides of the printed circuit board. Alternatively, the printed circuit board is preferably arranged in the axial direction of the crankshaft between various gears of the transmission. For example, the printed circuit board can be arranged between the first gear and the third gear. More preferably, the printed circuit board can be arranged on a side of the drive unit facing away from the output, i.e., in particular, on a side facing away from the output interface.Further alternatively, the circuit board can preferably be arranged on a side facing the output, i.e., on the side of the drive unit on which the output interface is located. This means that the circuit board can be arranged at a substantially outer end of the drive unit in the axial direction.

[0026] Preferably, the drive unit further comprises a connection element which is particularly designed for connecting a plug connection.

[0027] For example, the connection element can be designed as a plug element. The connection element is connected to the circuit board, in particular electrically. The connection element is arranged on a side of the circuit board facing away from the output interface. Alternatively, the connection element is preferably arranged on a side of the circuit board facing the output interface. In particular, the connection element is designed as an element that protrudes from the circuit board substantially in the axial direction of the crankshaft.

[0028] Furthermore, the invention leads to a vehicle that can be operated with muscle power and / or motor power, preferably an electric bicycle, which comprises the described drive unit.

[0029] Short description of the drawings

[0030] The invention is described below using exemplary embodiments in conjunction with the figures. In the figures, functionally identical components are identified by the same reference numerals. Here:

[0031] Figure 1 is a simplified schematic view of a vehicle with a drive unit according to a first embodiment of the invention,

[0032] Figure 2 is a sectional view of the drive unit of Figure 1,

[0033] Figure 3 is a perspective detailed view of the drive unit of Figure 1,

[0034] Figure 4 is a further perspective detailed view of the drive unit of Figure 1,

[0035] Figure 5 is a simplified schematic view of a drive unit according to a second embodiment of the invention,

[0036] Figure 6 is a simplified schematic view of a drive unit according to a third embodiment of the invention,

[0037] Figure 7 is a simplified schematic view of a drive unit according to a fourth embodiment of the invention, Figure 8 is a simplified schematic view of a drive unit according to a fifth embodiment of the invention,

[0038] Figure 9 is a simplified schematic view of a drive unit according to a sixth embodiment of the invention,

[0039] Figure 10 is a simplified schematic view of a drive unit according to a seventh embodiment of the invention,

[0040] Figure 11 is a simplified schematic view of a drive unit according to an eighth embodiment of the invention,

[0041] Figure 12 is a simplified schematic view of a drive unit according to a ninth embodiment of the invention, and

[0042] Figure 13 is a simplified schematic view of a drive unit according to a tenth embodiment of the invention.

[0043] Preferred embodiments of the invention

[0044] Figure 1 shows a simplified schematic view of a vehicle 100 comprising a drive unit 1 according to a first embodiment of the invention. The vehicle 100 is a vehicle that can be operated with muscle power and / or motor power, specifically an electric bicycle.

[0045] The drive unit 1 comprises a motor 2 (see Figure 2), which is in particular an electric motor. The motor 2 can be supplied with electrical energy by means of an electrical energy storage device 109 of the electric bicycle 100.

[0046] The drive unit 1 is arranged in the region of a bottom bracket of the electric bicycle 100. The motor torque generated by the motor 2 can provide motor assistance to the pedaling force generated by the muscular power of a rider of the electric bicycle 100.

[0047] The drive unit 1 is shown in detail in Figures 2 to 4 and is described in detail below. The drive unit 1 comprises a crankshaft 3, which can be connected to cranks 104 of the electric bicycle 100. This means that the crankshaft 3 can be driven by the rider's pedaling force. The crankshaft 3 has an output interface 35, to which an output element 107 of the electric bicycle 100 is connected in a rotationally fixed manner. In the illustrated embodiment, the output element 107 is designed as a chainring of a chain drive (see Figure 2).

[0048] The drive unit 1 also comprises a housing 9, within which all components of the drive unit 1 are preferably arranged, with the crankshaft 3 extending outward from the interior of the housing 9. The crankshaft 3 is rotatably mounted in the housing 9 of the drive unit 1 by means of two bottom brackets 61, 62.

[0049] In addition, the drive unit 1 comprises a transmission 4. The transmission 4 is designed to transmit torque between an output shaft 22 of the engine 2 and the crankshaft 3.

[0050] The transmission 4 is arranged along the direction of the crank axis 30 between the motor 2 and the output interface 35. With respect to a direction of travel A (see Figures 1 and 2), the output interface 35 is thus located on the right side of the crankshaft 3 and the motor 2 on the left side. In other words, the motor 2 forms the leftmost element of the drive unit 1.

[0051] Gearbox 4 is a two-stage spur gear. This means that gearbox 4 comprises several gears designed as spur gears that mesh with each other to transmit torque. Their arrangement is described in more detail below.

[0052] In the drive unit 1, the output shaft 22 of the engine 2 and the crankshaft 3 are arranged coaxially with one another. This means that the output shaft 22 and the crankshaft 3 are each arranged to rotate about a common crank axis 30. For this purpose, the output shaft 22 of the engine 2, which is in particular connected in a rotationally fixed manner to a rotor 21 of the engine 2, is designed as a hollow shaft. The crankshaft 2 extends through the output shaft 22. The crankshaft 3 and the output shaft 22 are rotatably mounted relative to one another by means of bearings 46, 47. For a compact geometry and robust mechanical support, the right-hand of the two bearings 47, which is located in the axial direction at the level of a first spur gear stage of the transmission 4, can, for example, be designed as a needle bearing.

[0053] The output shaft 22 of the motor 2 protrudes axially beyond the rotor 21. A motor toothing 44 is formed on this projecting portion of the output shaft 22.

[0054] The motor gearing 44 engages with a first gear 41 of the transmission 4. The first gear 41 is non-rotatably connected to an intermediate shaft 45 of the transmission 4. The intermediate shaft 45 extends along an intermediate shaft axis 40 and is arranged to be freely rotatable about this intermediate shaft axis 40.

[0055] In addition, the transmission 4 includes a second gear 42, which is also rotationally fixedly connected to the intermediate shaft 45. Preferably, the first gear 41, second gear 42, and intermediate shaft 45 can be formed together as a single, integral component.

[0056] In addition, the transmission 4 includes a third gear 43, which is arranged to rotate about the crank axis 30. A freewheel 5 is located between the third gear 43 and the crankshaft 3, which enables either a rotationally fixed connection or a freely rotatable arrangement of the third gear 43 and the crankshaft 3 relative to each other.

[0057] The torque transmission of the engine torque generated by the engine 2 can thus take place from the output shaft 22 via the engine toothing 44 and the first gear 41 to the intermediate shaft 45 and via the second gear 42 and the third gear 43 and the correspondingly switched freewheel 5 to the crankshaft 3.

[0058] The drive unit 1 thus offers, through the coaxial arrangement of rotor 2 and

[0059] Crankshaft 3 has the advantage that a particularly compact design of the drive unit 1 is possible. The motor 2, which geometrically forms the largest element of the drive unit 1, can be positioned particularly advantageously due to the coaxial arrangement to the crankshaft 3. Since, due to the special design of the transmission 4, the largest gear, namely the third gear 43, is also arranged on the crankshaft 3, a particularly small extension of the other parts of the drive unit 1 in the radial direction with respect to the crank axis 30 is possible, since the remaining transmission volume extends only slightly out of an axial projection surface of the motor 2. This can be seen, for example, in Figure 4, which shows a plan view of the drive unit 1 along the axial direction.

[0060] A further advantage is that the special design of the drive unit 1 with torque transmission via the intermediate shaft 45 allows the use of a spur gear as the transmission 4. Such a spur gear is characterized by a particularly high degree of efficiency, which ensures high efficiency in the operation of the drive unit 1.

[0061] Furthermore, the drive unit 1 can be provided in a simple manner with few and comparatively simple components, which can, in particular, reduce the costs for the drive unit 1. Furthermore, weight savings are possible due to the few and compact components of the drive unit 1.

[0062] The drive unit 1 also includes a system by which the rider's pedaling force and / or torque can be determined. This allows, for example, a rider's command to be determined, based on which the provision of the motor torque can be controlled.

[0063] The drive unit 1 comprises a detection device 8 which is designed to detect a bearing force on the output-side bottom bracket 62, that is to say on that one of the two bottom brackets 61, 62 which is arranged closer to the output element 107.

[0064] The detection device 8 comprises two force sensors 81, 82, each configured to detect a force in the tangential direction relative to the crankshaft 3. The two force sensors 81, 82 are attached to a slotted bearing shell 95, which is part of the housing 9. The output-side bottom bracket 62 is secured in the housing 9 by means of the bearing shell 95.

[0065] For example, the force sensors 81, 82 can be strain gauges or piezo elements, which allows a particularly simple and cost-effective design of the detection device 8.

[0066] The two force sensors 81, 82 are arranged such that the respective forces to be detected are aligned orthogonally to one another. Based on a previously known relative installation position of the two force sensors 81, 82 to one another, and for example by means of a prior calibration, a direction and magnitude of a momentary bearing force on the output-side bearing 62 can be determined. Based on this determined bearing force, and preferably based on the assumption that this bearing force is proportional to the pedaling force exerted by the rider of the electric bicycle 100 on the crank drive, the momentary rider's command can thus be determined using particularly simple and cost-effective means, based on which, for example, the controlled actuation of the motor 2 can take place.

[0067] The special arrangement and design of the detection device 8 for determining the rider's input based on the measurement of the bearing force at the output-side bottom bracket 62 allows for further optimization of the compactness of the drive unit 1. In particular, no components required for detection are required in the area of ​​the motor and / or transmission 4, enabling an optimal space-saving design in these areas, for example.

[0068] Further preferred embodiments of the invention are described below with reference to Figures 5 to 12. Each of these embodiments essentially corresponds to the first embodiment of Figures 1 to 4, with the difference of an alternative arrangement of the components of the drive unit 1.

[0069] Figure 5 shows a simplified schematic view of a drive unit 1 according to a second embodiment of the invention. In the second embodiment, the motor 2 is located on the right side of the drive unit 1 with respect to the direction of travel A. This means that the motor 2 is arranged in the direction of the crank axis 30 between the transmission 4 and the output interface 35.

[0070] Furthermore, the drive unit 1 of the second exemplary embodiment comprises a printed circuit board 7, which can, for example, be part of a control unit. The printed circuit board 7 is arranged on a side of the transmission 4 facing away from the output. This means that the printed circuit board 7 is located at the left end of the drive unit 1 with respect to the direction of travel A. This can, for example, enable good accessibility to the printed circuit board 7.

[0071] Figure 6 shows a simplified schematic view of a drive unit 1 according to a third exemplary embodiment of the invention. In the third exemplary embodiment of Figure 6, the motor 2 and the transmission 4 are arranged as in the second exemplary embodiment of Figure 5, i.e., the motor 2 is located between the output interface 35 and the transmission 4. In the third exemplary embodiment, the printed circuit board 7 is arranged within the transmission 4, in detail in the axial direction between the first gear 41 and the third gear 43. This makes it possible, for example, to provide a particularly compact arrangement and mechanical protection for the printed circuit board 7.

[0072] Figure 7 shows a simplified schematic view of a drive unit 1 according to a fourth exemplary embodiment of the invention. The fourth exemplary embodiment essentially corresponds to the second and third exemplary embodiments of Figures 5 and 6, respectively, with the difference of a further alternative arrangement of the printed circuit board 7. In the fourth exemplary embodiment, the printed circuit board 7 is arranged between the gearbox 4 and the motor 2. In detail, the printed circuit board 7 is arranged between the first gear 41 and the motor 2. The printed circuit board 7 is also arranged in the axial direction between the motor toothing 44 and the motor 2. This enables a further advantageous geometry and arrangement of the drive unit 1.

[0073] Figure 8 shows a simplified schematic view of a drive unit 1 according to a fifth exemplary embodiment of the invention. In the fifth exemplary embodiment of Figure 8, the motor 2 is arranged on the left side of the drive unit 1 with respect to the direction of travel A. This means that, in the direction of the crank axis 30, the gearbox 4 is located between the motor 2 and the output interface 35. The printed circuit board 7 is arranged centrally, i.e. in the axial direction between the motor 2 and the gearbox 4, in detail between the rotor 2 and the first gear 41 or motor toothing 44. This makes it possible to provide a particularly advantageous arrangement in which, for example, next to the printed circuit board 7, space is available in the axial direction at the level of the motor 2 for further components and / or connections of the drive unit 1.

[0074] Figure 9 shows a simplified schematic view of a drive unit 1 according to a sixth embodiment of the invention. In the sixth embodiment, the arrangement of motor 2 and transmission 4 corresponds to the arrangement of the fifth embodiment of Figure 8. In the sixth embodiment of Figure 9, the circuit board 7 is integrated into the transmission 4, in detail in the axial direction between the first gear 41 and the third gear 43.

[0075] Figure 10 shows a simplified schematic view of a drive unit 1 according to a seventh embodiment of the invention. In the seventh embodiment, the motor 2 and transmission 4 are arranged analogously to the fifth and sixth embodiments of Figures 8 and 9, respectively. The circuit board 7 is located to the right of the transmission 4 with respect to the direction of travel A. This means that the circuit board 7 is arranged between the transmission 4 and the output element 35.

[0076] Figure 11 shows a simplified schematic view of a drive unit 1 according to an eighth embodiment of the invention. The eighth embodiment of Figure 11 essentially corresponds to the fourth embodiment of Figure 7, wherein the drive unit 1 further comprises a connection element 6. The connection element 6 is designed in particular for connecting a plug connection (not shown).

[0077] For example, the connection element 6 can be designed as a plug. The connection element e is connected, in particular electrically conductively, to the printed circuit board 7 and arranged thereon. The connection element 6 is arranged on the side of the printed circuit board 7 facing away from the output, i.e. such that the connection element 6 protrudes from the printed circuit board 7 in the direction of the transmission 4. Figure 12 shows a simplified schematic view of a drive unit 1 according to a ninth exemplary embodiment of the invention. The ninth exemplary embodiment in Figure 12 essentially corresponds to the eighth exemplary embodiment in Figure 11, with the difference of an alternative arrangement of the connection element 6. In the ninth exemplary embodiment in Figure 12, the connection element 6 is arranged on the side facing the output interface 35, i.e. such that the connection element 6 protrudes from the printed circuit board 7 in the direction of the motor 2.

[0078] Figure 13 shows a simplified schematic view of a drive unit 1 according to a tenth exemplary embodiment of the invention. The tenth exemplary embodiment of Figure 13 essentially corresponds to the first exemplary embodiment of Figures 1 to 4, with the difference of an alternative arrangement of the engine freewheel. In detail, in the tenth exemplary embodiment, a freewheel 48 is arranged between the first gear 41 and the intermediate shaft 45. This enables decoupling or coupling between the engine 2 and the crankshaft 3 via the freewheel 45 on the intermediate shaft 45. The third gear 43 is connected to the crankshaft 3 in a rotationally fixed manner by means of a rotationally fixed connection 43a. This enables a particularly space-saving arrangement of the components, particularly in the area of ​​the crankshaft, in order to be able to provide a particularly compact drive unit 1.

Claims

Claims 1. Drive unit of a vehicle (100) operable with muscle power and / or motor power, comprising: - a motor (2) with an output shaft (22), - a crankshaft (3), and - a gearbox (4), - wherein the transmission (4) is designed to transmit torque between the output shaft (22) and the crankshaft (3), - wherein the output shaft (22) is arranged coaxially to the crankshaft (3), and - wherein the gear (4) is designed as a spur gear.

2. Drive unit according to claim 1, wherein the transmission (4) has an intermediate shaft (45) which is arranged parallel to the crankshaft (3), and wherein the transmission (4) is designed to transmit torque between the output shaft (22) and the crankshaft (3) via the intermediate shaft (45).

3. Drive unit according to claim 2, wherein the transmission (4) has a first gear (41) and a second gear (42), wherein the first gear (41) and the second gear (42) are connected in a rotationally fixed manner to the intermediate shaft (45).

4. Drive unit according to claim 2, wherein the transmission (4) has a first gear (41) and a second gear (42) and a freewheel (48), wherein the first gear (41) or the second gear (42) is connected in a rotationally fixed manner to the intermediate shaft (45), and wherein the freewheel (48) is arranged between the intermediate shaft (45) and the other gear (41, 42).

5. Drive unit according to claim 3 or 4, wherein the transmission (4) has a motor toothing (44) formed on the output shaft (22), and wherein the first gear (41) is in engagement with the motor toothing (44).

6. Drive unit according to one of claims 3 to 5, wherein the transmission (4) has a third gear (43) which is rotationally connectable to the crankshaft (3), and wherein the third gear (43) is in engagement with the second gear (42).

7. Drive unit according to claim 6, further comprising a freewheel (5) between the third gear (43) and the crankshaft (3).

8. Drive unit according to one of the preceding claims, wherein the transmission (4) is designed as a two-stage spur gear transmission.

9. Drive unit according to one of the preceding claims, wherein the motor (2) has a rotor (21) which is connected in a rotationally fixed manner to the output shaft (22).

10. Drive unit according to one of the preceding claims, wherein the output shaft (22) is designed as a hollow shaft, and wherein the crankshaft (3) is rotatably mounted within the output shaft (22).

11. Drive unit according to one of the preceding claims, further comprising two bottom brackets (61, 62), wherein the crankshaft (3) is mounted in a housing (9) of the drive unit (1) by means of the two bottom brackets (61, 62).

12. Drive unit according to one of the preceding claims, further comprising a detection device (8) which is configured to detect a bearing force on the output-side bottom bracket (62).

13. Drive unit according to claim 12, wherein the detection device (8) has two force sensors (81, 82), wherein each force sensor (81, 82) is configured to detect a force along a predetermined direction, and wherein the detection device (8) is configured to determine a bearing force direction and a bearing force amount of the bearing force at the output-side bottom bracket (62) based on the forces detected by the force sensors (81, 82).

14. Drive unit according to one of the preceding claims, wherein the crankshaft (3) has an output interface (35) which is designed for connection to an output element (107), and wherein the engine (2) is mounted on a the output interface (35), or wherein the motor (2) is arranged on a side of the transmission (4) facing the output interface (35). The drive unit according to claim 14, further comprising a printed circuit board (7), wherein the printed circuit board (7) is arranged in the axial direction between the motor (2) and the transmission (4), or between gears (41, 43) of the transmission (4), or on a side of the drive unit (1) facing away from the output, or on a side facing the output.Drive unit according to claim 15, further comprising a connection element (6), in particular for connecting a plug connection, wherein the connection element (6) is connected to the circuit board (7), and wherein the connection element (6) is arranged on a side of the circuit board (7) facing away from the output interface (35), or wherein the connection element (6) is arranged on a side of the circuit board (7) facing the output interface (35). A vehicle operable with muscle power and / or motor power, in particular an electric bicycle, comprising a drive unit according to one of the preceding claims.

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